Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Chip Amps Amplifiers based on integrated circuits

LM1875 bridge config
LM1875 bridge config
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 17th January 2008, 11:52 AM   #11
richie00boy is offline richie00boy  United Kingdom
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
LM1875 bridge config
Also note that the lowest impedance you can use is 8 ohms in bridge as each half effectively sees 4 ohms.
__________________
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, modules and more.
  Reply With Quote
Old 27th February 2012, 02:25 AM   #12
dannyjmf is offline dannyjmf  Saudi Arabia
diyAudio Member
 
dannyjmf's Avatar
 
Join Date: Feb 2010
Location: Riyadh Saudi Arabia
Quote:
Actually I was looking for someone that already tested the config
For the simplest method, go for Project 14 at ESP

Bridging Adapter For Power Amps

i've being using this method for my LM1875 DIY amp ... and it works nicely ....

Good luck
  Reply With Quote
Old 3rd March 2012, 05:59 AM   #13
mikeltuaz is offline mikeltuaz  Philippines
diyAudio Member
 
Join Date: Dec 2010
Location: cebu, Philippines
Send a message via Yahoo to mikeltuaz
could you share to us your configuration?? thanks
  Reply With Quote
Old 6th March 2012, 11:13 PM   #14
ChristianThomas is offline ChristianThomas  United Kingdom
diyAudio Member
 
Join Date: Feb 2006
Location: On a hill, in a wooden shack, next to the woods, in Somerset.
Tincho,

I know you have already got some 1875s, and by all means test them in bridged mode to see if it is alright, but they are completely the wrong chip to to use for any sort of sub, especially bridged. They simply don't have the current capability. You save yourself £3 by using them, but a single 3886 will outdo what they can do in a bridged configuration. You might just about get away with what you want in a simple parallel setup, where the current is halved for each, but I would not set too much store by just what you have to hand in front of you.
  Reply With Quote
Old 11th March 2012, 04:01 AM   #15
danielwritesbac is offline danielwritesbac  United States
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
What is the speaker load?
If 8 ohms, one pair of 2-chip parallel LM1875's might do for bridging.
If 4 ohms, one pair of 3-chip parallel LM3886's might do for bridging.

P.S.
Paralleled LM1875 into a 4 ohm load = 55 watts. Solo LM3886 into a 4 ohm load = ~45 watts due to on-chip limiter activation.
If you want more power than these, make BPA300 with 6 LM3886 and a small op-amp for phase inverter, and you can add a Stereo buffer (at subwoofer amp input) so you can downmix to mono without smashing the imaging of your main speakers.
  Reply With Quote
Old 11th March 2012, 04:13 AM   #16
danielwritesbac is offline danielwritesbac  United States
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Or the answer. . .
You may be able to sub LM1875 for TDA2030 and you may be able to sub MJL21193/MJL21194 for BD250/BD249. Maybe. But, with the sturdy helpers, the bridged LM1875 now pushes the 4 ohm woofer.
Attached Images
File Type: jpg circuit-power-amp-super-bridge-120w-by-ic-tda2030.jpg (90.0 KB, 349 views)
  Reply With Quote
Old 11th March 2012, 06:44 AM   #17
pacificblue is offline pacificblue  Germany
diyAudio Member
 
Join Date: May 2008
Quote:
Originally Posted by ChristianThomas View Post
they are completely the wrong chip to to use for any sort of sub, especially bridged.
It depends. For a top notch subwoofer that is supposed to deliver the lowest audible notes at original concert listening levels, any chip amp is the wrong choice.

If you choose the woofer and enclosure wisely, you can end up with a surprisingly decent sub for civilised listening levels even with an LM1875.

And in this case, where the subs only needs to improve the performance of PC speakers with a probably rather small woofer, an LM1875 is likely to be more than sufficient, whether bridged or not.
__________________
If you've always done it like that, then it's probably wrong. (Henry Ford)
  Reply With Quote
Old 1st April 2018, 03:28 AM   #18
Dimi Pana is offline Dimi Pana
diyAudio Member
 
Join Date: Nov 2011
Quote:
Originally Posted by dannyjmf View Post
For the simplest method, go for Project 14 at ESP

Bridging Adapter For Power Amps

i've being using this method for my LM1875 DIY amp ... and it works nicely ....

Good luck

Hi, I am trying to build a stereo power amp using four TDA2030A or (better) LM1875 in bridge mode. So two ICs bridged for each channel, I am hoping to get up to 35W per channel, but less is OK too.

Can you please help me formulate my design? The link does not work anymore, so I will need a schematic, plus any tips on how to do (exactly what you said!) a DIY LM1875 amp.

Thank you very much!
  Reply With Quote
Old 1st April 2018, 03:22 PM   #19
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
Link dont work because Rod's site moved.

Bridging Adapter For Power Amps

Also moved: http://www.ti.com/lit/an/snaa021b/snaa021b.pdf

Last edited by PRR; 1st April 2018 at 03:27 PM.
  Reply With Quote
Old 1st April 2018, 03:28 PM   #20
6L6 is offline 6L6  United States
diyAudio Moderator
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
LM1875 bridge config
There's a simple bridge LM1875 schematic on this site -

You don't need the bridging adaptor as one of the chips is setup using the inverting input.

Hacer amplificador de audio con LM1875, fuente simple o simétrica, simple o bridge

Click the image to open in full size.
  Reply With Quote

Reply


LM1875 bridge configHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tripath TA2024/20 Bridge/Parallel Config john65b Class D 19 10th June 2015 08:24 PM
Bridge LM1875 HS JhonDoe Chip Amps 17 30th July 2010 01:15 PM
Bridge amp config comparison panson_hk Solid State 13 2nd September 2007 10:32 PM
Nice simple parallel bridge config vortech Chip Amps 0 5th August 2005 01:08 PM
need help on my config hacknet Solid State 14 2nd December 2002 03:43 PM


New To Site? Need Help?

All times are GMT. The time now is 12:57 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki